Factors that Affect Vision

Being locked in the chamber P and looking at the white body RST, you must see the likeness of the objects V, X, Y.

Light is the movement or action that the sun or some other luminous body that pushes the fire-aether that is within all transparent bodies.

It bounces off the red object V. It gains its red color by making the fire-aether turn in circles around their centers after hitting it.

• This creates 2 movements [as VF and V5] that makes V look red when they
• The action of these two movements meet at point R.

The white body 1 reflects V without changing it. This goes towards the eye through the pores of this body. Those pores are very delicate and perforated on all sides. This makes you see the point R as red.

Light also bounces off of:

• yellow object X towards S
• blue object Y towards T

From there it is carried towards the eye. It makes you see S as yellow and T as blue.

Thus the 3 points R, S, T, appear of the same colors, and keeping the same order as the three V, X, Y, clearly show their likeness.

The perfection of this painting depends mainly on 3 things:

1. The pupil has some size

This will let several rays from each point of the object enter it.

• If the pupil were narrow, only a single ray could go to RST and would not have enough force.
• If the pupil were larger, but there were no refraction in the eye, the rays coming from the objects would spread out in all directions in RST.
  • The points V, X, Y would send 3 rays each towards R.
  • These would reflect from there together towards your eyes.
  • You would see point R as a medium color between red, yellow, and blue.

2. These rays must be refracted in the eye

In this way, those coming from different points are gathered in different points on the white body RST

3. The small filaments EN and the inside of the skin EF are black and the room P is entirely dark.

In this way, no light comes from elsewhere to disturb the action of these rays.

If EN, EF were not black, then they would not absorb the light that comes against them. The rays that come from RST towards them could return from there

• those of T towards S and R
• those of R towards T and S
• those of S towards R and T

These would disturb the action of each other.

The same would happen also to the rays that come from the room P towards RST, if there were any other light in this room, other than those sent by the objects V, X, Y.